Frequently asked questions

The science

The long-term solution

Interim beach works at Semaphore and Largs Bay

Securing the future of our coastline

The problem

What is the current state of our metropolitan beaches?

Some parts of the Adelaide beaches are experiencing significant sand loss and erosion of the sand dune system.  The sand along Adelaide’s coast naturally moves northward, by the wind and waves. This causes sand to build up on our northern beaches such as Semaphore, and causes sand loss and erosion along our southern and central coast such as West Beach and Henley Beach South. The State Government manages the metropolitan coastline to enable the community to enjoy sandy beaches. Sand carting has occurred across the metropolitan beach system for more than 40 years.

  • West Beach has suffered serious and ongoing erosion for a number of years.  At present, beach levels at West Beach and Henley Beach south are lower than at any other time since records began. 
  • From Henley Beach to the north, the beaches are in good condition as the sand lost from southern beaches drifts north. 
  • Sand continues to accumulate in Largs Bay, with wide dunes from around the Semaphore jetty northwards.
  • The beaches in the southern part of the coast (from Glenelg to Kingston Park) are generally stable because of successful beach management. The pipeline from Glenelg to Kingston Park currently pumps approximately 100,000m3 of sand successfully each year.

Read an article from InDaily ‘Shifting sands – why SA pays for an endless cycle of beach replenishment

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What has been the impact of our eroded beaches?

The erosion at West Beach has had a number of impacts.  Immediately north of the boat harbour the dunes have receded many metres, relying on regular recycling of sand from further north to manage the erosion. 

Further north, the beach at the West Beach Surf Life Saving club has been mostly eroded and the clubhouse, coast park and car park rely on a seawall for protection. 

At the northern end of the seawall, the erosion has lowered the beach so that the beach access ramp is sometimes closed.  The loss of dunes in this area has placed assets at risk, and is requiring regular beach replenishment with sand from Semaphore South to maintain protection levels.

The erosion has progressed to affect Henley Beach South, with much of the sand dunes in front of the seawall being affected.  

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What would happen to West Beach if this replenishment doesn't occur?

West Beach has suffered serious and ongoing erosion for a number of years.  At present, beach levels at West Beach and Henley Beach south are lower than at any other time since records began. 

The erosion at West Beach has had a number of impacts.  Immediately north of the boat harbour the dunes have receded many metres, relying on regular recycling of sand from further north to manage the erosion. 

Further north, the beach at the West Beach Surf Life Saving club has been mostly eroded and the clubhouse, coast park and car park rely on a seawall for protection. 

At the northern end of the seawall, the erosion has lowered the beach so that the beach access ramp is sometimes closed.  The loss of dunes in this area has placed foreshore assets at risk, and is requiring regular beach replenishment with sand from Semaphore South to maintain protection levels.

The erosion has progressed to affect Henley Beach South, with much of the sand dunes in front of the seawall being recently eroded and beach access affected.  

The beach replenishment will protect our most vulnerable and eroded beaches including West Beach and Henley Beach South, with benefits to other beaches as sand moves northward.

The science

What is the DHI report? What does it say?

DHI has completed a report on West Beach coastal processes modelling: assessment of coastal management options. The report was commissioned by the Department for Environment and Water, the Coast Protection Board, the City of Charles Sturt and West Beach Parks.

At West Beach (the section of coastline running north from the West Beach boat harbor at West Beach Parks to the Torrens Outlet), the loss of sand each year is significant, and the research undertaken by DHI has shown that it is greater than previously estimated.

The report makes it clear that even if current management activities are maintained, erosion will continue around West Beach and Henley Beach South, and progressively move north.

The report tested out three alternative scenarios for managing the beach and dune erosion at West Beach, with their results modelled. All three options involve beach replenishment, and varied by bringing in differing amounts of sand over different timescales. A fourth option – do nothing – does not help the situation.

Feedback from local government, industry and community stakeholders, together with the best available research and modelling has been taken into consideration in final decision making.

Who commissioned the DHI report and why?

In 2017, the Department for Environment and Water commissioned the coastal processes modelling study in order to better understand the coastal processes at West Beach and to examine alternative management options. This was needed because of the ongoing loss of sand each year at West Beach. Following a competitive tender process, DHI was commissioned to undertake the study.

During the course of the study, the scope was amended to expand the analysis of beach profiles along the entire system from Kingston Park to Largs Bay, to enable a better understanding of the influence of management of adjacent beaches on West Beach and vice versa.  This expanded analysis also provides insight into the management of the entire Adelaide beach system.

The long-term solution

What is the government doing to address the problems in the long term?

The government is investing $48.4 million to the metropolitan coast over four years. This consists of $20 million for additional sand including approximately 500,000 cubic metres (m³) of newly sourced sand; and $28.4 million for the completion of a sand recycling pipeline from Semaphore to West Beach, as well as sand dune restoration and revegetation in partnership with local councils and coastal community groups.

The beach replenishment will put sand on our most vulnerable and eroded beaches including West Beach and Henley Beach South, with benefits to other beaches as sand moves northward.

The announcement has been informed by research completed in 2018 by external consultants DHI on behalf of the Department for Environment and Water, the Coast Protection Board, the City of Charles Sturt and West Beach Parks.

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When will it start? When will the pipeline be built?

In 2019/20 and 2020/21, we’ll be increasing our beach replenishment to West Beach and Henley Beach South each year to match current rates of loss and stabilise and maintain the beaches and dunes in the short term.

Then in 2021/22, a large scale replenishment using sand from an external source is planned to be delivered. This will raise the beach levels and boost sand dune buffers at West Beach and Henley Beach South with benefits to other beaches as sand moves northward.

Following the project planning phase (including detailed designs, engineering, community consultation and approvals), the pipeline is planned for construction in 2021/22, with the pipeline operational by end 2022/23.

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Where will the sand come from and why do we need an ‘external’ sand source?

There is a limited amount of sand in Adelaide’s beach system. To find a suitable external sand source for the large scale beach replenishment, we will investigate offshore sand deposits as well as some land-based sources. See 'Why can’t external sand be brought in now?'

Sand will also continue to be carted by truck from Adelaide’s northern beaches (including the Semaphore South breakwater and from between the Semaphore and Largs Bay jetties) in 2019/20 and 2020/21. This is being done to restore sand that is currently being lost from West Beach and Henley Beach South each year while external sand is sourced and the sand recycling pipeline is constructed. 

Watch the video to learn more about how we manage Adelaide’s beaches

How will this impact our northern beaches, like Semaphore?

Management of the entire metropolitan coast needs to be adaptive and flexible. Our beaches are constantly changing and sand is naturally moved northward by the wind and waves, which causes sand to build up on our northern beaches, such as Semaphore, but causes erosion along our southern and central coast such as Seacliff, Brighton and Henley Beach.

A sustainable approach to managing our beaches involves recycling sand from areas of where sand builds up to areas of loss. Investigations have taken place to see if sand in other northern beaches is suitable to use for beach replenishment while the pipeline is built and before sand from an external source is available. 

Starting in late 2019, sand will be collected from beaches between the Semaphore jetty and Largs Bay jetty, which have large sand accumulations, to supplement the amount of sand collected from the Semaphore South breakwater.  Whilst the breakwater is designed to trap sand as it naturally moves northward, we need to rest this supply so it can replenish. (See ‘Why is sand being collected between the Semaphore and Largs Bay jetties?’)

Why are we building a sand recycling pipeline and where will it be located?

A sand recycling pipeline from Semaphore to West Beach will provide an efficient means to recycle sand. This will provide a long term solution to keeping sand on our most exposed and vulnerable beaches.

Pipelines provide more flexibility in managing our beaches – with multiple intake and discharge locations allowing sand to be picked up where there is an accumulation and delivered to locations most at need across the beach system. We have seen this success with the Glenelg to Kingston Park pipeline, which currently pumps approximately 100,000m3 of sand each year.

Another major benefit of the pipeline is reducing the use of trucks for sand recycling, making it safer for the community, as well as reducing noise, congestion and the impact of trucks on roads.

The exact location of the pipeline and how it will be built will be determined in the planning and design period starting in 2019-20.

You can find out more about the existing sand recycling pipeline and how it works, including technical information here.

What impacts will building the pipeline have on our beaches and dunes?

We will minimise the impacts as much as possible during construction. The community will be kept informed and have opportunities to find out more in the coming months.

There will be short-term impacts from construction.  Disturbance of existing dunes and ecological communities will be minimised and disturbance of key areas will be avoided.  

The works will recycle sand each year to maintain critical dune buffers.This provides the base for dune restoration for the foreshore at West Beach and Henley Beach South in particular. The government will partner with the community and councils to revegetate the foreshore and develop stable sand dunes with vibrant ecological communities.

How will the community be kept informed? What opportunities are there to get involved?

There will be some impact for many residents and beach goers as these works are undertaken. We will keep the community informed during all phases of the projects.

There will be opportunities to find out more in the coming months, including through public events and information sessions. Public notices will be published in local papers and we will also meet with local community groups.

We will work in partnership with local councils and coastal community groups on sand dune restoration and revegetation works. 

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Don’t we already have a pipeline?

Adelaide’s two existing underground sand recycling pipelines - Glenelg to Kingston Park and Torrens Outlet to the West Beach dunes - were completed in 2013 to transfer a slurry of sand and seawater from beaches where sand is building up, to the eroding beaches further south.

The pipeline from Glenelg to Kingston Park currently pumps approximately 100,000m3 of sand successfully each year.

This project will extend the pipeline from the northern beaches, to connect to the existing infrastructure at Torrens Outlet to the West Beach dunes.

What happened to the sand carted to West Beach over the last year?

The West Beach area has been eroding since the 1960s and has received many hundreds of thousands of cubic metres of sand to manage the area over the years. Previously it was estimated that sand depleted from the West Beach area was about 50,000 m³/year. Most of this is through northward movement, with very little lost offshore.

The new research undertaken by DHI estimates that annual depletion is actually between two and three times that rate, meaning that even when current replenishment activities are taken into account there is a net annual loss of approximately 60,000 m³.

Windy weather and strong waves have caused erosion to continue at West Beach, and when beaches are replenished with sand it is normal for some of it to be washed away during the next storm. If the replenishment sand wasn’t there, then West Beach would be even more eroded and exposed.

Much of the sand that is washed offshore during storms is moved back onshore during calmer periods, so it is not wasted.  This sand will also help maintain beaches as it drifts to the north.

Adding sand to the Adelaide beach system benefits more than just West Beach, it also ensures there is more sand to flow between the beaches and be recycled.

Did the department consider structures like groynes to try to reduce West Beach sand drift north?

By building a structure or structures like groynes and breakwaters that slow sand movement along the coast, the area in the vicinity of the trapped sand can be protected.  However, the coast to the north (down-drift) of the structure will then be starved of sand unless the area is replenished.

By focussing on replenishment as the main strategy for protection rather than using structures, the protection of Adelaide’s beaches can be achieved without the additional cost and side effects of expensive structures, which would tend to interrupt our long sandy beaches.

Options involving the construction of hard engineering structures to re-orientate the West Beach shoreline were considered by DHI and included offshore breakwaters and headland control structures. A range of risks and disadvantages were identified with these options. The DHI report does not model any management options that use structures to retain sand on the beaches. 

Why does Seacliff beach look so good? How has dune restoration helped?

During the 1980s and 90s, the Seacliff and Brighton coast was suffering from severe erosion that threatened the foreshore. To address this a large scale beach replenishment with sand sourced externally was undertaken. This formed and stabilised the dunes, with the active involvement of local community dune care groups and volunteers. The local council supported these efforts with ongoing restoration involving drift fencing trapping sand to control sand drift, access control, weed removal and re-vegetation. The operation of the sand recycling pipeline from 2013 onwards has further stabilised this part of the coast and allowed dunes to flourish.

Seacliff Beach 1981Seacliff beach 2012

What is being done to help beaches outside of Adelaide?

Local councils play a critical role in protecting regional assets from coastal hazards and maintaining coastal areas for all South Australians and tourists.  The state government has committed an additional $4 million over 4 years to regional coasts to repair, restore and sustain them in partnership with local councils.  This support responds to the increasing demand for coastal protection infrastructure to address hazards like flooding and erosion. 

The program will be open to councils with a particular focus on the outer metro and regional areas. Learn more.

Interim beach works at Semaphore and Largs Bay

Why is sand being collected between the Semaphore and Largs Bay jetties?

The state government’s long term strategy to manage the erosion at West Beach and Henley Beach South includes a commitment to match the rate of sand loss at these beaches by carting sand by truck in the short term while new sand is sourced from outside of the Adelaide beach system and a sand recycling pipeline from Semaphore to West Beach is built.  (See ‘When will it start? When will the pipeline be built?’).

Due to the natural northward movement, sand builds up at Semaphore. Much is captured at the Semaphore South breakwater. Sand has also accumulated at beaches between the Semaphore and Largs Bay jetties. Sand now needs to be collected from the beach between the Semaphore jetty and Largs Bay jetty to supplement the amount of sand collected from the Semaphore South breakwater.  Whilst the breakwater is designed to trap sand as it naturally moves northward, we need to rest this supply so it can replenish. 

The beach between the Semaphore and Largs Bay jetties will only be used as a sand source when the primary source at the Semaphore South breakwater needs to naturally replenish.

When will the work be done and how long will it take?

Works to widen the beach access path at Semaphore will commence in October 2019. While the beach access path works are undertaken, sand will continue to be carted from the primary sand source at the Semaphore South breakwater. 

Once the beach access path is completed, sand carting from between the Semaphore and Largs Bay jetties will commence and continue until the next school holidays in mid-December 2019.

The sand carting (which includes carting from both the Semaphore South breakwater and the beach between the Semaphore and Largs Bay jetties) will occur three to four times over the next two years, and last for a duration of 8 to 10 weeks each time. All sand carting will avoid school holiday periods and weekends.

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Technical and environmental information

How much sand will be sourced from between the Semaphore jetty and Largs Beach jetty?

The beaches between the Semaphore and Largs Bay jetties will only be used as a sand source when the Semaphore South breakwater needs to naturally replenish. 

The exact quantity of sand to be sourced from this area will depend on the weather and how quickly the Semaphore South breakwater replenishes with sand.

Why isn’t sand collected from the beaches further north, like North Haven?

Historically, sand at the northern end of Largs Bay has proven to be unsuitable for replenishing beaches further south on the Adelaide coast as it is finer than the native beach sand and would wash away much more quickly.  The most recent analysis shows that while suitable sand can be found to just north of Largs Bay jetty, the build-up of sand beyond that would not be suitable for replenishing West Beach or adjacent beaches.

The properties of Adelaide’s natural beach sand has been thoroughly investigated to inform beach management decisions and help identify suitable sources of sand for beach replenishment. 

What will the likely impacts to the dunes between Semaphore and Largs Bay jetties be?

The dunes in between the Semaphore and Largs Bay jetties vary from 80 metres wide to over 100 metres wide, and sand will be sourced from the beach where the dunes are wider.  

Any indication of foredune erosion at this location would be closely monitored to ensure the foreshore remains protected and the wider dune system maintained.

It is expected that this impact will be short-term until Semaphore beach naturally replenishes with sand that slowly travels north again, enabling the foredune to rebuild.

How will the impacts to the dunes be managed?

We acknowledge the great work that dune care groups do to look after our beaches and their extensive local knowledge of the dunes. We will work with them to minimise the impacts to our beaches and dunes during this time. There will be opportunities in the future for community groups to partner with the local council for dune care grants to further improve the coastal biodiversity.

We will continue to monitor the beaches and dunes to ensure the foreshore remains protected.

Have environmental impacts been considered?

Semaphore has been used as a sand source area at various times since the 1970s and has naturally replenished without causing significant environmental impacts. 

The approach for managing Adelaide’s beaches is based on expert advice underpinned by decades of data collected, including current and historical survey information on beach profiles and independent technical reports. 

At the location between the Semaphore and Largs Bay jetties, the government’s beach profile data indicates that there is sufficient dune volume buffer and the area will steadily build up again through natural processes. A team of environmental specialists monitor and assess Adelaide’s beaches regularly. 

The Department for Environment and Water works with Birdlife Australia to ensure any impacts to shorebirds are avoided or minimised.

The Securing the future of our coast project will improve dune biodiversity in the longer-term along Adelaide’s coast by stabilising the beaches and dunes with a steady supply of replenishment sand and through partnerships with council and community groups. 

Widening the beach access to accommodate the sand carting equipment will require the removal of some weeds and common vegetation and will not have a significant environmental impact.

Why isn’t more sand being collected from the Semaphore South breakwater?

Over the years, sand has regularly been moved from the Semaphore South breakwater to West Beach and Henley Beach South. Once sand builds up again at the Semaphore South breakwater (as wind and waves naturally moves sand northward along Adelaide’s coast), sand will be collected from there again.

Since October 2018 approximately 100,000 cubic metres of sand (about the equivalent of 40 Olympic sized swimming pools) has been carted from the Semaphore South breakwater to West Beach and Henley Beach South.

Once the pipeline is built, how much sand will be sourced from Semaphore?

Once operational, the sand recycling pipeline will be used to source sand from areas where sand is built up to replenish areas that are eroding further south.  Analysis of the beach profiles conducted by the Department for Environment and Water will provide information on where sand is accreting or eroding and inform these decisions.  The Semaphore South breakwater, designed to trap sand for replenishment, will continue to be a primary source of sand. 

Average natural sand movement northwards along the coast is approximately 100,000 cubic metres each year, and this will need to be matched by replenishment of West Beach at the southern end of the pipeline pumping system.  The volumes of sand eroding and building up along the beach system will vary from year to year, depending on the shape and height of the sea bed, the weather and storms and this will influence the amount of sand which needs to be collected for replenishment.

Traffic, access and community safety

What is the traffic route that will be used for sand carting in Semaphore?

When sand is being collected from the beach between the Semaphore and Largs Bay jetties, the following streets in Semaphore will be used by trucks transporting the sand:

  • Hall Street, Semaphore – between Military Road and Esplanade
  • Esplanade, Semaphore between Hall Street and Hannay Street
  • Hannay Street, Semaphore – between Esplanade and Military Road
  • Military Road – between Hannay Street, Semaphore and West Lakes Boulevard.

View a map of the route.

The route has been determined in consultation with the City of Port Adelaide Enfield.  The route was selected based on technical specifications, such as the width of streets and location of roundabouts and with the aim to minimise disturbance to the community as much as possible.  Community safety is a priority, and the government will closely monitor the road and traffic management of sand carting.   

Following community concern, investigations have been undertaken to consider turning maneuvers and road safety, and investigating the integrity of the roads to facilitate heavy vehicle movements of the kind required for sand carting.

The trucks will adhere to South Australian road rules and safety regulations. Access to and from people’s houses will not be blocked by the trucks passing by. We apologise in advance for the inconvenience during this time.

It is expected that there will be around 8-10 trucks on the road every hour during operations (between 7:30 am and 5:00 pm on weekdays).  Outside of operating hours some machinery will be stored in the nearby carpark and the rest will be stored offsite. A longer term benefit of the sand recycling pipeline will be a significant reduction in the use of trucks on roads in the future.

Will the trucks carting the sand be covered to stop it blowing onto roads?

Yes. Sand is loaded into road trucks and covered to prevent loss of sand in transit. When necessary mechanical sweeping of roads and the beachside carpark will be undertaken.

How will community safety be ensured? / How are traffic risks managed?

Community safety is a priority and the government is minimising risks and disturbance to the local community, beach goers and road users during any sand carting works (for example, by not working at night and avoiding weekends and school holidays).

The community and road users are informed to take extra care on the beaches, streets and surrounding area during works and adhere to safety signs that are in place during operations.

The sand carting operation employs qualified contractors. The successful contractor is required to develop a job safety plan and a thorough risk management plan. This includes safe management between the work and members of the public (and will include for example, placement of pedestrian traffic management signage and traffic controllers).

Traffic control complies with relevant Australian Standards and Code of Practice. Traffic controllers and/or signage is provided where necessary to warn pedestrians of truck movements, including, for example, a traffic controller to manage the truck crossings of the Coast Park shared use path.

Trucks adhere to South Australian road rules and safety regulations. Access to and from people’s houses will not be blocked by the trucks passing by.

We are also liaising with Surf Life Saving SA and the Semaphore Life Saving Club regarding beach safety.

How can I access the beach during the works?

There are multiple access paths to the beach from the same car parking area for use by the public.

A traffic controller will be provided to manage the truck crossings of the Coast Park shared use path.

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Image: Beach access path location at Semaphore. View a flyer about the works.

How wide will the access path be at Semaphore?

The beach access path needs to be 4.5 metres wide with a 7 metre ‘apron’ at the beach entry point.

Will the access path be able to be used by the community in the future?

The beach access path may be able to be used in the future as an accessible path for wheeled mobility aids and those who have difficulty walking to reach the firmer sand at the water’s edge. 

What do residents and beachgoers need to do?

The community and road users are asked to:

  • Take extra care on the beaches, streets and surrounding area during works.
  • Adhere to safety signs and directions.

What about issues with trucking noise and air pollution?

The sand carting will be undertaken in a manner that meets legal requirements for noise and air quality. This includes only operating on weekdays, and using roadworthy and registered trucks. 

Why aren’t other roads also being used in addition to Hall Street and Hannay Street?

The route has been determined to minimise disturbance as much as possible and to use primary access roads (Military and The Esplanade).

It is not practical to use multiple routes to distribute the traffic load as this disperses trucks through more residential streets and many of these are not suitable for truck movement.

Why can’t the sand be trucked along the beach to Semaphore South and then on the public roads from there?

Sand from between the Semaphore and Largs Bay jetties cannot easily be carted to Semaphore South along the beach because the machinery and trucks required would have difficulty in moving underneath the Semaphore jetty.  Exposure to tides and waves means it is difficult to maintain access under the Semaphore jetty on a daily basis, for the large articulated trucks.

Why isn’t dredging or a barge used to cart sand instead?

Shifting sand by dredging it onto a barge would be severely limited by weather conditions. The amount of sand needed to match the rate of loss from West Beach and Henley Beach South could not be moved efficiently and cost-effectively with a dredge.

Why can’t external sand be brought in now?

There is a limited amount of sand in Adelaide’s beach system and to find a suitable external sand source for the large scale beach replenishment will take time. We will investigate offshore sand deposits as well as some land-based sources.

These investigations and other planning and approvals are required before the external sand is delivered. The large scale replenishment using sand from an external source is planned to be delivered in 2021/22. View the project timeline here.

Why aren’t structures like groynes built to try to reduce sand drift north?

By building a structure or structures like groynes and breakwaters that slow sand movement along the coast, the area in the vicinity of the trapped sand can be protected.  However, the coast to the north (down-drift) of the structure will then be starved of sand.

By focusing on replenishment as the main strategy rather than using structures, the protection of Adelaide’s beaches can be achieved without the additional cost and side effects of expensive structures, which would tend to interrupt our long sandy beaches.

Options involving the construction of hard engineering structures to re-orientate the West Beach shoreline were considered by DHI and included offshore breakwaters and headland control structures. A range of risks and disadvantages were identified with these options.  The DHI report does not model any management options that use structures to retain sand on the beaches.

Has the department looked at the work done to manage beaches in other areas?

Beach management strategies vary across Australia and internationally due to differences in coastal processes, climate and landscape.  The approach for managing Adelaide’ beaches is based on expert advice underpinned by decades of data collected, review and assessment of methods used around the world, consideration of the issues specific to Adelaide’s beaches, and including current and historical survey information on beach profiles and independent technical reports.

Community engagement

What engagement with local businesses has there been in Semaphore?

The government has been liaising with local businesses, including the Palais Hotel and Semaphore Road traders association. We are working to minimise disturbance to the community as much as possible by not operating during school holidays or on weekends.

What community engagement has happened so far in Semaphore?

Community events have been held where the community were invited to learn more, see concept plans and talk to the project team. The first event was held on 29 July 2019 at the Port Environment Centre. The second event was held on 26 August 2019 at the Port District Football Club. The government has also been liaising with local councils, businesses and organisations, such as dune groups and surf life saving clubs.

Who can I contact for more information?

For enquiries contact the Department for Environment and Water on 8124 4928 or email DEWCoasts@sa.gov.au

To find out more, visit environment.sa.gov.au/coasts